The present disclosure herein relates to a material for an organic electroluminescent device and an organic electroluminescent device including the same. For example, the present disclosure herein relates to a material for an organic electroluminescent device having high emission efficiency and long life, and an organic electroluminescent device including the same.
Recently, the developments of organic electroluminescent (EL) displays as one type of image displays are being actively conducted. Organic EL devices are so-called self luminescent displays and are different from liquid crystal displays. The organic EL devices display images by emitting light from a luminescent material (including an organic material) in its emission layer via recombination of holes and electrons injected from an anode and a cathode in the emission layer.
As an organic EL device, an organic device may include, for example, an anode, a hole transport layer disposed on the anode, an emission layer disposed on the hole transport layer, an electron transport layer disposed on the emission layer and a cathode disposed on the electron transport layer. Holes are injected from the anode, and the injected holes move via the hole transport layer and are injected into the emission layer. Electrons are injected from the cathode, and the injected electrons move via the electron transport layer and are injected into the emission layer. The injected holes and electrons recombine to generate excitons in the emission layer. The organic EL device emits light utilizing light generated by the radiation deactivation of the excitons. The configuration of the organic EL device is not limited thereto, however, and various modifications may be possible.
When organic EL devices are applied to display apparatuses, the high efficiency and long life of the organic EL devices are required. However, in an organic EL device—particularly in a blue emission region when compared to a green emission region and a red emission region, the driving voltage is high and the emission efficiency is insufficient. To realize the high efficiency and long life of an organic EL device, ways of increasing the normalization, stabilization and durability of the hole transport layer have been examined.
As a hole transport material utilized in a hole transport layer, various compounds such as an aromatic amine compound have been utilized. However, issues related to resolving the short life of the device remain. As a useful material for increasing the life of the organic EL device, for example, an amine derivative substituted with an aryl group or a heteroaryl group has been suggested. However, an organic EL device utilizing the above-mentioned material has insufficient emission life. Thus, an organic EL device having higher efficiency and long emission life is desired at present.